xenon vs inert gas

xenon and inert gas both are nouns.

Word	Noun	Adjective	Verb	Adverb
xenon	Yes	No	No	No
inert gas	Yes	No	No	No

As nouns, inert gas is a hypernym of xenon; that is, inert gas is a word with a broader meaning than xenon:

xenon: a colorless odorless inert gaseous element occurring in the earth's atmosphere in trace amounts
inert gas: any of the chemically inert gaseous elements of the helium group in the periodic table

Other hypernyms of xenon include argonon, noble gas.

xenon (noun)	inert gas (noun)
a colorless odorless inert gaseous element occurring in the earth's atmosphere in trace amounts	any of the chemically inert gaseous elements of the helium group in the periodic table